Method of producing mineral wool



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Patented Jan. 28, 1941 UNITED STATES lPATENT OFFICE METHOD or PRonUcmG MINERAL woor.

l Raymond C. Johnson and Harold J. Rose. Pittsbui-gh, Pa., assignors to Anthracite Industries,

Claims.

This invention relates to the production of mineral ,wool and consists in a method, whereby materials not heretofore recognized to be sources of mineral Wool may be resorted to for such production.

'I'he accompanying drawing illustrates diagrammatically the method of the invention.

Inl, an application for Letters Patent of the United States, Serial No, 223,687, led August 8, 1938, Raymond C. Johnson has described the derivation of mineral wool from the ashes of industrial furnaces; and in a. second application, Serial No. 232,609, filed on even date herewith, the said Johnson has defined the wastes of coalmining and coal-washing operations as source materials for the production of mineral wool. The present invention recognizes all these sources, and consists in a method of dealing with any and all these materials with the production of mineral wool.

The practice of the invention involves the operation of a slagging gas producer. A slagging gas producer consists essentially of a refractorylined furnace chamber of essentially cylindrical shape standing in vertical position, to which fuel is fed from aboveand combustion-sustaining air from below, while steam is injected into the furnace charge at an intermediate point in the height of the furnace. The parts are so proportioned and arranged that a combustion zone is maintained at an intermediate portion of the vertical extent of the furnace chamber. The gas formed by the action of steam in the air-blown fuel bed consists chieiiy of carbon monoxide and hydrogen. From the upper part of the furnace chamber the gas is drawn off; from below, the slag is discharged.

in practising the present invention the furnace is charged with material of the kind named above, typically the ash from an industrial coal-burning furnace. This ash is a heterogeneous mixture of unburned or partially burned fuel, together with inorganic, mineral residues that commonly include, in predominant quantities, alumina and silica. in physical condition it may range from dusty, friable and finely divided material to large hard clinkers.

The furnace being soV charged, and beingoperated, the gas produced by operation is used as fuel to generate steam, and the steam so generated is employed to blow to the condition of wool the molten slag as it ows from the furnace.

Referring to the drawing, the furnace chamber is indicated at I; its charging door at 2, and its slag-delivery orice at 3. Air ports 4 are diagrammatically indicated, through which combustion-sustaining air is blown into the furnace charge. -Above the level of the air ports steam ports 5 are arranged, and through these the steam is injected that combines with the hot solid fuel to form the gaseous product described. Through ports 6 the producer gas is drawn off.

Adjacent the furnace I is arranged a boiler 1. This boiler is heated by the burning of the gas produced in furnace l and delivered through ports 6, In general, it will be necessary to burn no more than a part of the producer gas to generate steam for the blowing of wool; the surplus may be used for any other desired purpose. Adjacent the ash delivery 3 from furnace l is ar- 15 ranged a nozzle 8 and to this nozzle steam from boiler 'l is fed, and from the nozzle the steam is projected in a jet. The jet plays upon the escaping stream of molten slag, and blows it to wool, within the wool room 9.

Steam from boiler i may be delivered, not through `nozzle 8 only, to blow the slag to wool. but to ports 5 also, to serve in the production of the gas, as already indicated. The injected steam not only serves to accomplish the 'reaction de- 25 scribed; it serves also to control temperature,- and to prevent sintering and clogging of the fuel bed above the combustion zone. The air that enters through ports t into the furnace is introduced under pressure, and to such end a .blower it may be provided. LTiurtherinore, the introduced air will be heated to high degree for its service, and, to such end, the producer gas, serving as already descrlbed, to heat the water in boiler l and so to produce steain for the op- 3d eration described, may be made to serve further, in heating the air that is blown through ports d into the furnace. This also is indicated in the drawing. The degree to which the air is preheated will vary inversely with the combustible 4o content of the furnace charge. The sensible or latent heat from the gases may be used to4 drive the blower it also.

The fuel ashes that are introduced into the furnace i may be introduced in the condition in which they come from the ash pit of the furnace in which they were formed, or they may be worked upon, in preparation for their further treatment. Large lumps may be broken; fines may be sifted out and otherwise disposed of. Or, the rines may be briquetted and returned to the mass. Additions may be made, either of fuel in solid or in liquid state (in case the ash is very lean in carbon content), or of flux (in case the ash is low in lime). The heating effect of the ls gas produced may be supplemented, if need be, by resortf to additional sources of heat.

Similarly as the invention is practiced upon the ashes formed in industrial furnaces, it may be performed upon the refuse of coal-mining and coal-washing operations, and upon carbonaceous shales so low in carbon content as not to justify their use a's fuel. It may, indeed, be performed upon coal itself; but, ordinarily, coal of quality such as to render it serviceableE as fuel will, economically, be so used; and, in consequence, the eld of this invention will, in actual practice, be limited to operation upon material not generally serviceable in the industry as fuel. In case it be used upon coal, the potential heat is such in quantity that, ordinarily, it will be advantageous to add incombustible material suitable for the end in view-that is to say, lime or silica, or both.

We claim as our invention:

1. The method herein described of producing mineral wool whichA consists in placing carbonaceous material that contains a large proportion of mineral matter capable of being blown into wool into a slagging gas-producer, burning said material under conditions to produce producergas and to melt said mineral matter, conducting said gas into a steam generator and burning said gas therein to generate steam, and blowing said molten mineral matter into wool with said steam.

2. The method herein described of producing mineral wool which consists in placing carbonaceous material that contains a large proportion of mineral matter capable of being blown into wool into a slagging gas-producer, burning said material while steam is injected into it under conditions to produce producer-gas and to melt said mineral matter, conducting said gas into a steam generator and burning said gas therein to generate steam, blowing said molten mineral matter into wool with a portion of said steam and injecting another portion of said steam into the gas-producer.

3. The method herein described of producing mineral wool which consists in placing coal ashes that contain a large proportion of mineral matter capable of being blown to wool into a slagging gas-producer, burning said coal ashes under conditions to produce producer-gas and to melt said mineral matter, conducting said gas into a steam generator and burning said gas therein to generate steam, and blowing said molten minerai matter into wool with said steam.

4. The method herein described of producing minerai wool which consists in placing in aslagging gas-producer carbonaceous material that contains a large proportion of mineral matter capable of being blown into wool, and adding flux to such material, burning said material under conditions to produce producer-gas and to melt said mineral matter and ux, conducting said gas into a steam generator and burning said gas therein to generate steam, and blowing the molten material into wool with said steam.

5. The method herein described of producing mineral wool which consists in placing in a slagging gas-producer coal ashes that contain a large proportion of mineral matter capable of being blown into wool, and adding flux to such ashes, burning' the ashes under conditions to produce producer-gas and to melt said mineral matter and ilu conducting said gas into a steam generator and burning said gas therein to generate steam, and blowing the molten material into wool with said steam.

RAYMOND C. JOHNSON. HAROLD J. ROSE. 

